Generically comparable bogies are already known, where the axle of the running wheels rests on a pair of leaf springs attached to the frame. Such a bogie is described e.g. by John R. Tucker in "Railway Engineer International", Vol. 5 (1980) March/April, pages 44-46. The running wheels are arranged outside the slewing ring. With the known bogies, lateral tracking stability is assured by horizontally arranged and relatively rigidly mounted guide wheels which are pressed against a lateral guidance.
A particular disadvantage of the known bogies is that wide gauges and therefore also relatively large track cross sections are required because of the position of the running wheels. For aesthetic as well as cost reasons, however, it would be better to keep the track cross sections as small as possible. Furthermore, the known bogies are distinguished by partly unsatisfactory damping and spring characteristics.